num = int(input("请输入一个整数:"))

if num < 0 or (num % 10 == 0 and num != 0):
    print("这不是一个回文数")
elif not num // 10:
    print("这是一个回文数")
else:
    hou = 0
    while(num > hou):
        hou = hou * 10 + num % 10
        num //= 10
    if num == hou or num == (hou // 10):
        print("是回文数")
    else:
        print("不是回文数")